docs: def prototype_adjacency(self, n_block_features, alpha):
          """Build a new graph.
  
          Doc for ".create(n_features, alpha)"
  
          Parameters
          -----------
          n_features : int
  
          alpha : float (0,1)
              The complexity / sparsity factor.
  
              Each graph will have a minimum of
  
                  n_blocks * ceil(alpha * n_block_features)
  
                  where
  
                  n_block_features = floor(n_features / self.n_blocks)
  
              edges and exactly this amount if chain_blocks=False.
  
          Returns
          -----------
          (n_features, n_features) matrices: covariance, precision, adjacency
          """
          return lattice(
              self.prng,
              n_block_features,
              alpha,
              random_sign=self.random_sign,
              low=self.low,
              high=self.high,
          )